The present invention relates generally to producing a hole in an article, and in particular, to an apparatus and method for producing a plurality of screw holes in an article of wood or wood product using a high pressure device and a punch.
Typically, conventional drilling machines are used to form screw holes in wood panels. These machines tend to be bulky, slow and costly, and the drilling operation tends to produce a substantial amount of dust and debris which increases clean-up costs. When these machines are used to produce holes in laminated particleboard, the resulting holes tend be defined by a non-uniform, non-compact wall. As a result, the holes must be drilled relatively deep to provide sufficient holding power for the fastening of screws to the low-density particleboard. In addition, it is difficult to drill holes in the edges of a wood panel with conventional drilling machines.
A number of prior art devices use a stationary pneumatic cylinder in cooperation with a ball and die to punch a plurality of holes through a web of material which continuously moves between the cylinder and die. Devices of this type are disclosed in U.S. Pat. Nos. 4,674,372 (Mobley) and 3,463,042 (Goldman). In U.S. Pat. No. 3,996,832 (Schubert et al.), a plurality of stationary pneumatic cylinders are used in cooperation with a plurality of dies and flat punches having a curved cutting edge for punching a slot through a plastic container.
In U.S. Pat. No. 3,167,151 (Jack et al.), a method of forming a plurality of perforations in an acoustic panel is disclosed which includes the step of pressing a stepped punch having a flat end into a surface of the panel.
In U.S. Pat. No. 3,143,026 (Akerson), a tool having a shank and a tapered end portion with a flat end is disclosed for punching holes in acoustic panels.